J. Sylhet Agril. Univ. 3(2):233-243, 2016 ISSN: 2308-1597

FISH DIVERSITY OF KAPTAI LAKE IN A AREA TO

S S Basak1, M A Basher1, A K Saha2 and N C Roy*3

1Bangladesh Fisheries Research Institute, Riverine Sub- Station, Rangamati 2District Fisheries Officer, Department of Fisheries 3Department of Fish Biology and Genetics, Sylhet Agricultural University, Sylhet-3100,

Abstract

An investigation was carried out in fish landing centers and fish markets adjacent to Kaptai lake, Rangamati to identify the potentiality of fish landing centers, the diversity of available fish fauna and the marketing channel. The study was done by questionnaire interviews (QI) of fish traders, focus group discussions (FGD) and secondary data collection from April 2014 to March 2015 in 03 landing centers and 15 markets of Rangamati district. A total of 84 species of fishes, which consists of 75 finfish and 9 shellfish were identified during the study period. Among 75 finfish, 52 were indigenous freshwater fish species, 10 exotic species and 13 marine species. In shellfish group, 7 prawn and shrimp, 1 crab and 1 pond tortoise species were found. Different types of freshwater fish, marine fish, crustacean and dry fish were found in the investigated markets of Rangamati town. The most abundant freshwater fish species were Catla catla, Labeo rohita, Clarias batrachus, Cirrhinus cirrhosus, Channa punctatus. Few numbers of marine fishes including Latescal carifer, Euthynnus affinis and Mugil cephalus were also recorded. Macrobrachium rosenbergii and Penaeus monodon were found most abundantly during the study period. A total 20 species were threatened according to IUCN red list of Bangladesh including 7 vulnerable, 10 endangered and 3 critically endangered species out of 54 threatened fishes in fresh waters of Bangladesh. Among 7 vulnerable fishes 6 were available, 1 was rarely available. Among 10 endangered species 9 were available and 1 was rarely available. Among 3 critically endangered species 1 species was found available and 2 species were rarely available. Ten exotic fish species (Hypophthalmicthys molitrix, Ctenopharyngo donidella, Cyprinus carpio, Puntius gonionotus, Oreochromis niloticus, Oreochromis mossambicus, Pangasius hypopthalmus, Mylopharyngodon piceus, Aristichthys nobilis and Clarias gariepinus) were found in Kaptai lake during the study period. Fish biodiversity of Kaptailake is decreasing day by day due to habitat degradation and different manmade causes. Proper conservation measures should be taken to protect the threatened fish species from extinction.

Keywords: Kaptai lake, fish fauna, diversity, landing center and fish market.

Introduction

Inland aquatic habitats of Bangladesh are rich in faunal diversity containing at least 265 species of finfish, 63 species of prawn, and several species of turtles, tortoises, freshwater mussels and other living aquatic organisms (Rahman, 2005). Bangladesh is also rich in marine fishes having 475 marine finfish and 36 Marine shrimp species (DoF, 2013). Almost all varieties of fishes, both inland (fresh and brackish) and marine water fish species are available in the fish landing centers of Rangamati town.

The Kaptai reservoir is one of the largest man-made freshwater lake in South-east Asia (Fernando, 1980), was created in 1961 by damming the River Karnaphuli at Kaptai, mainly to provide electricity by hydropower. Fisheries, flood control, navigation, drainage and irrigation were considered as secondary options. The reservoir covers an area of approximately 68,800 ha and constitutes a significant component of inland water resources accounting for 46.8% of the total pond area of Bangladesh (Ahmed, 1999). Fishing in the Kaptai reservoir was leased in 1963 for 99 years to BFDC, which has landing station, ice plant and refrigeration facilities. The management of the Kaptai reservoir

*Corresponding author: N C Roy, Department of Fish Biology & Genetics, Sylhet Agricultural University, Sylhet- 3100, Bangladesh, E-mail: [email protected]

Basak et al. (2016) fisheries basically pertains to: (a) restricting fishing to certain periods, (b) issuing licenses to the fishermen, (c) implementing the Fisheries Act, and (d) using the most advocated and widely practiced stocking and recaptures techniques.

Fish landing center is the place where different types of fresh and fisheries commodities are accumulated from different sources of waterbodies such as river, beel, pond, gher, estuaries and sea, and these fishes are transferred from here to local markets via different intermediaries and channels (Ali et al., 2004). Fish landing center plays a vital role in quick and smooth disposal of fresh fish and in this regard the fish landing centers of Rangamati town may be the point of observation to survey the availability of fish species.

Rangamati region is recognized as the fisheries zone of the country. A number of huge varieties fish are available in the landing centers of Rangamati town. Both inland and marine fish species are found in these centers. Availability of species in fish landing centers and markets which would be helpful to provide a preliminary knowledge about fish fauna, mostly to know about the fish fauna in the biggest artificial lake-Kaptai. However, no methodical study has been carried on the fish diversity; catch composition, seasonal variation of fish availability and the causes of decreasing fish diversity which is consequently limit the establishment of biodiversity conservation strategies. Therefore, considering the above mentioned facts the present study has been set up to assess the diversity of available fish fauna in this important lake of Bangladesh.

Materials and Methods

Fish market There are many markets in around Rangamati town. Among these 09 fish markets were selected for study. The study area includes- Bonorupa bazar, Rijab bazar, TNT bazar, Tobolchori bazar, Assambosti bazar, Ghagra, Vetvedhi, TNT bazaar and College ghat.

Landing centers Three fish landing centers were surveyed during the study period. The landing centers are located in main town that includes BFDC fish landing center, Kaptai fish landing center and Mohalchori fish landing center in Rangamati.

Selection of samples Total sample size of the study was 100 of which 70 were fish traders, 10 aratdar and 20 were fish retailer. Fish traders were categorized into three groups namely bepari, aratdar and retailer.

Preparation of questionnaire Three different questionnaires were carefully prepared to interview the selected retailer, aratdar and bepari of this study.

Period of data collection For the study the data were collected during the months of April 2014 to March 2015.

Data collection Several visits were made in each of the landing centers and fish markets of Rangamati town. As the supply of the fishes varied with seasons, the data were collected in different seasons i.e. throughout the years by repeated visit in the landing centers and markets.

Questionnaire interview and focus group discussion (FGD) For questionnaire interviews, simple random sampling method was followed for 3 bepari, 2 aratders and 3 retailers in each study sites per visit.

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Results and Discussion

Fish landing center plays a vital role in quick and smooth disposal of fresh fish and in this regard the fish landing centers of Rangamati town may be the point of observation to survey the status of fish, source of fish and dry fish availability. A total 84 species of fishes were found. A good number (62) of freshwater fish species, marine species (13) were supplied to Rangamati town from Kaptai lake and different places of the country. Fifty four (52) freshwater fishes, 10 exotic, 13 marine, and 7 prawn/ shrimp, 1 crab and 1 pond tortoise species were found during study period. However, freshwater fishes were mainly coming from different types of waterbodies (River, Kaptai lake, Creeks, etc.) of greater Rangamati district. Major dominant species were Chapila (G. chapra), Bata (L. bata), Chapila (Gonialosa manmina), Kachki (C. soborna), Air (Mystus aor), Kuncho chingri (Machrobrachium lamarrei), Kajoli (Ailia coila), Mola (Amblypharyngodon mola), Tilapia (Oreochromis mossambicus).

Out of 74 species of fin fishes, 30 were abundant in winter (WN), 19 were abundant in summer (SM) and the rest 26 were available throughout the year (TY) (Tables 1, 2 and 4). All the exotic species were freshwater fishes and they were found all the year round as they are being cultured by commercial fish farmers. Nine (9) shellfishes were found most of the landing centers and fish markets. Different species of freshwater fish, marine fish, crustaceans and exotic fish species and their scientific names, family, common names and local names are presented in Tables 1, 2, 3 and 4.

Table 1. Availability of freshwater fish species in different fish markets and fish landing centers of Kaptai lake

Seasonal Family Lacal name Common name Scientific name abundance 1. Mastacembelidae Tara baim One stripe spiny Macrognathus aculeatus WN eel/Lesser spinyeel Guchibaim Striped spiny eel/ Macrognathus pancalus WN Barred spinyeel 2.Osphronemidae Khalisha/ Giant gourami Colisa fasciatus TY Khailsha Lalk halisha Red gourami Colisa lalia TY 3.Anabantidae Koi Climbing perch Anabas testudineus TY 4.Gobiidae Bele Tank goby Glossogobius giuris WN 5.Nandidae Bheda Mud perch Nandus nandus SM 6.Sciaenidae Poa Pama Otolithoides pama SM 7.Ambassidae Ranga chanda Indian glassy fish Parambassis ranga WN Lomba chanda Elongate glass-perchlet Chanda nama SM 8.Synbranchidae Kuicha Cuchia Monopterus cuchia TY 9.Chanidae Shol Striped snakehead Channa striatus SM Gajar/ Gajal Giant snakehead Channa marulius SM Taki, Lata Spotted snakehead Channa punctatus SM 10.Belonidae Kaikka Needle fish Xenentodon cancila WN 11.Heteropneustide Shing Stinging catfish Heteropneustes fossilis SM 12.Clariidae Magur Air breathing catfish Clarias batrachus WN 13.Pangasidae Pangas Yellowtail catfish Pangasius pangasius TY 14.Schilbeidae Bacha Bacha Eutropiichthys vacha WN Kajuli Gangeticalilia Ailia colia WN Banspata River catfish Ailia punctata WN Batasi Indian potasi Pseudeutropius WN artherinoides 15.Siluridae Kani Pabda Indian butter catfish/ Ompok bimaculatus SM pabo catfish Boal Freshwater shark Wallaga attu WN Modhu pabda Pabdah catfish Ompok pabda SM

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Tengra Striped dwarf catfish Mystus vittatus WN Golsha tengra Gangeticmystus Mystus bleekeri WN Bujuri-tengra Tengramystus Mystus tengara WN 16. Bagridae Ayre Long-whiskered catfish Sperata aor WN 17.Cobitidae Gutum Cross fish Lepidocephalichthys SM guntea Rani loach Botia dario WN 18.Cyprinidae Rui Rohu Labeo rohita TY Catla Catla Catla catla TY Mrigel Mrigal Cirrhinus cirrhosus TY Kalibaus Black rohu Labeo calbasu TY Bhangon bata Bata labeo Labeo bata SM Sarpunti Olive barb Puntius sarana TY Tit punti Ticto barb Puntius ticto SM Jat punti Pool barb Puntius stigma SM Mola punti Glass barb Puntius guganio SM Bashpata Sind danio Devario devario WN Bhangon Bogalabeo Labeo boga SM Mola Molacarplet Amblypharyngodon mola SM Dhela Cotio Rohtee cotio WN Dankina Rasbora Rasbora rasbora WN Chela Silver razorbelly Salmostoma bacaila SM minnow Shada ghonia Kurialabeo Labeo gonius WN 19.Notopteridae Chital Humped featherback Notopterus chitala WN Foli Grey featherback Notopterus notopterus WN 20.Engraulidae Phasa Gangetichairfin Setipinna phasa WN anchovy Chapila Indian river shad Gudusia chapra WN Kachki Ganga river Corica saborna WN

SM= summer, WN= winter, TY= throughout the year

Table 2. Marine fish species observed in fish market of Kaptai lake, Rangamati

Family Lacal Name English Name Scientific Name Seasonal abundance 1.Centropomidae Bhetki Vetki Lates calcarifer TY 2.Tunnidae Tuna Born maittya Euthynnus affinis WN 3. Harpadontidae Loitta/ Nehari Bombay duck Harpadon nehereus WN 4. Sciaenidae Poa Pama Pama pama WN Vola/ Lalpoa Silver jew Johnius argentatus TY Sadapoa Silver jew Otolithes argentatus TY 5. Polynemidae Lakhua Indian threadfin Leptomelanosoma indicus WN Lakhua Indian salmon Polynemus indicus WN 6. Mugilidae Bhangan Mullet Mugil cephalus SM 7. Trichiudae Churi Ribbon fish Lepturacanthus savala TY 8. Scatophagidae Chitra Spotted butterish Scatophagus argus TY 9. Stromatidae Rup chanda Chinese pomfiret Pampus chinensis TY 10. Engraulidae Phasa Hairfin anchovy Setipinna taty SM

SM= summer, WN= winter, TY= throughout the year.

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Table 3. List of crustaceans observed in fish landing centres of Kaptai lake, Rangamati

Family Lacal Name English Scientific Name Seasonal Name abundance 1. Palaemonidae Golda chingri Fresh water Macrobrachium rosenbergii TY prawn Chatka chingri Monsoon Macrobrachium malcolmsonii TY river prawn Pata chingri River prawn Macrobrachium rude TY

Gura chingri Spider Nematopalaernon tenuipes TY prawn 2. Penaeidae Bagda chingri Giant tiger Penaeus monodon TY shrimp Chaka chingri Indian white Penaeus indicus TY shrimp Horina chingri Brown Metapenaeus monoceros TY shrimp 3. Portunidae Shela kakra Mud crab Scylla serrata TY

4. Bataguridae Pond tortoise Kasim Melanochelys trijuga TY

TY= throughout the year

A total 84 species of fishes were found during study period of which 62 freshwater fishes (52 indigenous and 10 exotic), 13 marine, 7 prawn and shrimp, 1 crab and 1 pond tortoise species. During investigation, Cypriniformes was recorded as the most diversified fish group in terms of both number of species and individuals. Galib et al. (2013) reported a total of 63 species of fishes belonging to 41 genera, 23 families and 9 orders in the Choto Jamuna River, which was more or similar with the findings of the present study.

Table 4. List of exotic fish species observed in the fish markets of Kaptai Lake, Rangamati

Family Lacal Name Common Name Scientific Name Seasonal abundance 1.Cyprinidae Silver carp Silver carp Hypophthalmichthys molitrix TY Carpu Common carp Cyprinus carpio TY Bighead carp Bighead carp Aristichthys nobilis TY Black carp Black carp Mylopharyngodon piceus TY Rajputi/ Silver barb Puntius gonionotus TY Thai sarputi Grass carp Grass carp Ctenopharyngodon idella TY 2. Clariidae African catfish North African Clarias gariepinus TY catfish 3.Pangasiidae Thai pungus Big-catfish Pangasiu shypophthalmus TY 4.Cichlidae Tilapia Mozambique Oreochromis mossambicus TY tilapia Nilotica Nile cichlid Oreochromis niloticus TY

TY= throughout the year

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During the study period 20 threatened fish species (IUCN, 2003) have been found in Kaptai lake. Among 20 species 16 were found to be available, 4 rarely available and 34 were not available during the study period. Availability of three categories critically endangered, endangered and vulnerable fishes from Kaptai lake are presented in Table 5.

Table 5. A list of threatened (critically endangered, endangered and vulnerable) fish species available in the Kaptai lake

Biodiversity status Scientific name Local name Present biodiversity status of according to IUCN Kaptai lake Bangladesh (2003) Available Rarely Not available available Critically Labeo nandina Nandina √ endangered Labeo boga Bhangon/Bata √ Labeo pangusia Ghoramuikha √ Puntius sarana Sarputi/sorolputi √ Rita rita Rita √ Channa barca Piplashol √ Tor tor Mohashol √ Sisorr habdophurus Chenua/sisor √ Bagarius bagarius Beghair √ Pangasius pangasius Pangus √ Eutropichthys vacha Bacha √ Clupisoma gaura Gaura √ Endangered Labeo calbasu Kalbasu √ Labeo gonius Ghonia √ Labeo bata Bata/Vangon bata √ Osteobrama cotio Dhela √ Bengalae langa Along/Sefati √ Chela laubuca Kashkhaiya/Laubuka √ Crossocheilus latius Kalabata √ Notopterus chitala Chital √ Barilius bendelisis Hiralu/Joia √ Barilius vogra Khoska/Chedra √ Botia dario Rani/beti/Betia √ Botia lohachata Rani/putul/beti √ Batasio tengara Tengra √ Raimas bola Bhol/vole √ Rasbora rasbora Darkina √ Aorichthys seenghala Guizza air/Air √ Ompok bimaculatus kani/Boali pabda √ Ompok pabda Modhu pabda √ Ompak pabo Pabda √ Silionia silondia Shilong √ Chaca chaca Chaka/chaga √ Dermogynys pusillus Ekthota √ Scatphagus argus Bistara √ Badis badis Napti koi √ Channa marulius Gajar √ Microphis deokata Kumirer khil √ Ctenops nobilis Neftani √ Mastacembelus Baim/ shalbaim √ armatus Vulnerable (VU) Notopterus notopterus Foli √ Anguilla bengalensis Bamos/baobaim √ Cirrhinus reba Raikh/bata/Vagna √ Puntius ticto Titpunti √ Sperata aor Ayre/aor √

Channa orientalis Telotaki/chang √

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Macrognathus aral Tara baim √ Chanda nama Chanda √ Pseudembasis ranga Rangachanda √

Nandus nandus Meni/bheda √

Mystus cavasius Golsa /golsatengra √ Ailia coila Kajuli √ Plotosus canius Gang magur /Kanmagur √ Monopterus cuchia Kuicha √

Considering threatened species, 30% were found available, 7% rarely available and 63% were not available during the study period (Fig. 1).

Available Rarely available 30% Not available

63% 7%

Fig. 1. Availability of threatened fish species from Kaptai lake

Biodiversity status of critically endangered fish species in Kaptai lake Three (3) critically endangered fish species were found in Kaptai lake. Among them 1 species (E. vacha) was found available (8.33%), 2 species (P. sarana and L. boga) were rarely available (16.67%). On the other hand, 9 species (B. bagarius, S. rhabdophurus, C. barca, T. tor, R. rita, C. gaura, L. nandina, L. pangusia, P. pangasius) were not available (75%) during the study period (Table 5 and Fig. 2).

8.33%

16.67% Available 75% Rarely available Not available

Fig. 2. Percentage of critically endangered fish species

Biodiversity status of endangered fish species in Kaptai lake Ten (10) endangered species were found in the Kaptai lake where 9 species (C. marulius, M. armatus, O. pabda, B. tengara, L. bata, L. calbasu, L. gonius, O. cotio, N. chitala) were found available (32%) and 1 was rarely available (4%). On the other hand, 18 species (64%) were not available (O. paba, S. silondia, C. chaca, D. pusillus, M. deokata, S. argus, B. badis, C. nobilis, A. seenghala, R. bola, B. Lohachata, B. bendelisis, B. vogra, B. elanga, C. laubuca B, Dario, R. rasbora and C. latius) (Table 5 and Fig. 3).

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Available Rarely available Not available

32%

64% 4%

Fig. 3. Percentage of endangered fish species

Biodiversity status of vulnerable fish species in Kaptai lake According to the Red list of ICUN Bangladesh, 2003 Seven (7) vulnerable species were found in Kaptai lake of which 6 were available (43%) and 1 rarely available (7%). It was also observed that 7 species not available (50%) during the study period (Table 5 and Fig. 4).

Available

Rarely available

Not available

43% 50%

7%

Fig. 4. Percentage of vulnerable fish species

From Kaptai lake a total of 20 threatened fish species were indentified during the study period, out of 54 threatened fishes as reported by IUCN Bangladesh (2003). Among 20 threatened fish species there were 7 vulnerable, 10 endangered and 3 critically endangered species. Alam (2004) recorded a total of 73 species of fish belonging to 47 genera, 25 families, two species of prawn and 1 species of dolphin from Kaptai lake. Kachki (C. soborna), Chapila (G. chapra), air (M. aor), Foli (N. notopterous), Nilotica (O. niloticus), Kuncho chingri (M. lamarii) and Ghoria (L. gonious) were dominant in the past and also in the present study. In the present study, among 20 threatened fish species 16 species (29.62%) were found available. Some of the threatened fish species were found in good quantities during the study period indicating these fishes may not be threatened in this lake. Rahman and Hasan (1992) observed that a total of 49 species of indigenous and 5 exotic fishes existed in Kaptai lake. Halder et al. (1991)

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Fish diversity of Kaptai lake recorded a total of 71 fish species including 5 exotic fish and 2 species of prawn from Kaptai lake. Although foli (N. notopterous), air (Sperata aor), kajoli (A. coila), punti (Puntius ticto) were vulnerable but they were found available in Kaptai lake. Therefore, these species although threatened in the context of Bangladesh, may not be threatened for Kaptai lake. Silonia silondia, Bagarius bagarius, Tor tor, Otolithoides pama, Clupisoma goura are critically endangered or extinct species not found in Kaptai lake. Setipinna phasa, Ompok bimaculatus, P. sophore, P. sarana, Chanda nama, C. reba fish species were very rare in Kaptai lake.

Ten exotic fish species have been found from Kaptai lake such as Hypophthalmicthys molitrix. Ctenopharyngodon idella, Cyprinus carpio, Puntius gonionotus, Oreocromis niloticus, O. mossambicus, Pangasius hypopthalmus and Mylopharyngodon piceus, Aristichthys nobilis and clarias gariepinus. Among them P. ginionotus and H. molitrix were found less than others species during the study period. From the observation of availability of fishes in different landing centers/markets, it was found that 88.6% of the total fish were transported to Rangamati town from Kaptai Lake, Rangamati region and other 11.4% from outside of Rangamati region. The fish composition in different fish markets is presented in Table 6.

Table 6. Market shares in main fish species in different fish markets of Rangamati town

Sources of fish Fish Bonorupa Rijab TNT Tobolchori Vetvedhi Average in the markets bazar (%) bazar (%) bazar (%) bazar (%) bazar (%)

Rangamati Indian major carps 45 45 44 43 45 44.4 region (88.6%) Catfishes 13 13 12 11 12 12.4 Tilapia 5 6 6 5 7 5.8 SIS 9 6 8 5 10 9.6 Thai Koi 5 5 5 6 3 4.8 Shrimp 2 5 2 2 4 3 Others 7 5 11 9 6 8.6 Outside of Hilsa 6 7 8 6 7 6.8 Rangamati Carps (Indian and 4 3 3 4 2 3.2 (11.4%) exotic) Others (including 2 2 1 1 1 1.4 marine fish) Total 100 100 100 100 100 100

Virtually most of the fish (88.6%) were brought from different areas of the Rangamati districts and adjacent districts like Chittagoag, Cox’ Bazar, Fenietc the rest (11.4%) were brought from external source in Bonorupa bazar, Rijab bazar, TNT bazar, Tobolchori bazar, Assambosti bazar and other fish markets from local sources. Main source of these fishes were different Kaptailake, creeks, ponds, beels and rivers of Rangamati district and adjacent districts in Rangamati. Hossain (2009) studied that 29% of fish supplied in the markets were carps, 28% SIS, 2% hilsha, 24% catfish, 4% prawn/ shrimp, 3% tilapia, 2% koi, and 8% others. About 90% of fishes have been transported from the rural areas of the district and adjacent district like Netrokona, Jamalpur and Krishoregonj. The rest 10% comes from external sources in Mechhua bazar, Natun bazar, Railway market and Pourashova bazar. Whereas (100%) of the fish species were brought from different area of the district and adjacent district in Keyotkhali bazaar, K.R. market, Shesmor bazar, and Sutiakhali bazar.In this study a total of 100 fish species were found in the landing centers of Rangamati town out of 260 freshwater fishes. Chowdhury and Iqubal (2007) carried out an investigation on the fish species availability in the fish landing centers of Dhaka. They observed a total of 98 inland and marine water fish and crustacean species and out of 98, 87 species belonged to fin fish. Among the finfish species, 52 were freshwater species.

A total of 13 marine fish species were recorded. Among the marine fish species 5 species were found in winter, 2 species in summer and the rest 6 species all the year round. In case of winter season, fish supply is comparatively higher than other season because the sea remains calm in winter season (Ali et al., 2004). A total of 9 shellfishes were observed in the landing centers of Rangamati town. Chowdhury and Iqubal (2007) reported that 11 shellfishes were observed in the landing centers of Dhaka city. They were also found 13 exotic freshwater fish species round the year as they were being cultured by commercial fish farmers.

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Seasonal variation of fish species Seasonal variation in the abundance of different species of fish in the Kaptailake is shown in the Fig. 5. Water level in Kaptai decreased in Junuary than other month. Abundance of fish increased during November and gradually shows declining trends onward from January. Once again it exhibits gradual rise from April. Fish abundance was low in December and January (Fig. 5).

700000 Rangamati

576078 Kaptai 600000 550579

Mohachari 500000 471854 469381 466244 413970 424102 400000 357839 353219 362509 320829 346156 280206

300000 250901 249915 Production (Kg) Production 201270 187158 186973 163123 200000 141480

62412 57076 100000 40191 325 279 55428 51252 20598 35759 33717 22016 0 15358 136 8387 0 20 533 Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Fig. 5. Monthly variation of fish production in different landing centers

The highest number of fish species was found in Rangamati fish landing center and lowest number in Mohalchari fish landing center. The present study covered twelve months. Among this 12 month in November availability of fish was high and lowest in January. In September fish production in Rangamati is 5,76,078 kg, Kaptai 4,13,970 kg and in Mohalchari 62,412 kg. In January 2,01,270 kg in Rangamati, 1,63,123 kg in Kaptai and 15,358 kg in Mohalchari fish landing center. Fish availability decreased gradually from December to February and gradually increased from March to April. From May, fishing in Kaptai lake for an indefinite period has been banned to conserve the fish species every year. During this period, mother fishes lay eggs while fish fries are also released in lake. Mohsin (2009) studied on the seasonal abundance of fin fishes in the Pabda River at , Bangladesh. Maximum 67 species were recorded in the month of August, September and December of 2009 and in May and June of 2010; whereas the lowest number of fish species (65) was observed in April 2010.

Conclusion The study preliminary attempts to understand the status and current worries of fish diversity of Kaptai lake, Bangladesh. Loss of many commercially important fish species is the current alarming issue and its conservation is the only solution for this problem. Though this lake have been conserved by many rules and regulations but due to the lack of proper scientific data-base, it is becoming more difficult to select proper management and conservation strategy. However, present study has revealed some recommendations like ensuring water flow, developing fishermen’s awareness, preventing indiscriminate fishing of larvae and juveniles, effective implementation of existing fisheries laws and declaration of fish sanctuary to save diversity of Kaptai lake. Extensive research is required to prepare better data-base information on biodiversity and fisheries with abundance problems aiming to develop practical rule and regulations.

Acknowledgements We express our heartfelt gratitude to the local retailer, aratdar, fishermen of fish market and fish landing centers for their extensive support during sample collection and we also express thanks to all staff of the Bangladesh Fisheries Research Institute (BFRI), Riverine Sub-Station, Rangamati for their assistance during laboratory and field works.

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References Ahmed K K. 1999. Options for the management of major carp fishery in the Kaptai Reservoir, Bangladesh’, PhD dissertation, School of Environment, Resources and Development, Asian Institute of Technology, Bangkok. Ali M Y, Salim G M, Mannan M A, Rahman M M, Sabbir W and Mursida A. 2004. Fish species availability observed in the fish landing centers of district in Bangladesh. J. Biol. Sci. 4(5):575-580. Alam M D. 2004. A study on the present status and Alternate strategies for the management of Kaptai reservoir, MS thesis, Department of Fisheries Management, Bangladesh Agricultural University, Mymensingh. Chowdhury M M and K F Iqubal. 2007. A survery on the availability of fish species in the landing centers of Dhaka city in Bangladesh. Bangladesh J. Zool. 35(2):259-267. DoF (Department of Fisheries). 2013. Fish week Compendium, Department of Fisheries, Ministry of Fisheries and Livestock, Government of the People’s Republic Bangladesh, Dhaka.144p. Fernando C H. 1980. The fishery potential of man made lakes in South East Asia and some strategies for its optimization’, in BIOTROP Anniversary Publication, Bogor, Indonesia. pp. 23–28. Galib S M, Naser S M A, Mohsin A M B, Chaki N and Fahad F H. 2013. Fish diversity of the River ChotoJamuna, Bangladesh: Present status and conservation needs. Aquatic Biodiversity Laboratory, Department of Fisheries, Faculty of Agriculture, University of Rajshahi, Rajshahi-6205, Bangladesh. Int. J. Biodiv. & Conser.5:389-395. Hossain M F. 2009. Abundance of fish and shellfish species in some Mymensingh markets.MS thesis, Department of Aquaculture, Bangladesh Agricultural University, Mymensingh. 54p. Rahman A K A. 2005. Freshwater fishes of Bangladesh. 2nd ed., Zool. Soc. Bangladesh, Dhaka, Bangladesh, xviii+ 394p. Halder G C, Mazid M A, Haque M K I, Huda M S and Ahmed K K. 1991.A review on the fisheries fauna of the Kaptai reservoir.Bangladesh J. Fish. 14:127-135. ICUN Bangladesh. 2003. Bangladesher Biponnoprani (Red Book of Threatened Animals), ICUN- The world conservation Union XIV 294. Rahman M M and Hasan M R. 1992.A study on fish and fisherman of Kaptai Lake in Bangladesh. Report submitted in University Grand Commission, Dhaka. 49p.

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